Scammell TRMU - AIRFIX & IBG

[TeeELL]

If anyone is interested I have a few resin printed parts to improve the running gear on the Airfix Scammell tractor unit:  front axle and perch bar, front wings, rear ‘twin driving axle units’.  I can supply alternative tread pattern wheels.
If you have the IBG 1/72 model, you may have noticed that the manufacturer has used the same size wheels/tyres on the rear of the Scammell, I have replacement ‘twin driving axle units’ and wheels with a variety of tread patterns.  PM me for details.

[badger]

On 16/11/2022 at 08:29, TeeELL said:

If anyone is interested I have a few resin printed parts to improve the running gear on the Airfix Scammell tractor unit:  front axle and perch bar, front wings, rear ‘twin driving axle units’.  I can supply alternative tread pattern wheels.
If you have the IBG 1/72 model, you may have noticed that the manufacturer has used the same size wheels/tyres on the rear of the Scammell, I have replacement ‘twin driving axle units’ and wheels with a variety of tread patterns.  PM me for details.

PM inbound!!

[badger]

My wheels arrived yesterday courtesy of @TeeELL.

 

Absolutely fantastic and a massive improvement over the kit offerings.

 

All the best

Ben

[TeeELL]

Since my last post I have been looking at creating some additional parts to ‘improve’ the Airfix rendering of the Scammell TRMU 30.  You may be aware that the front profile of the roof is far too low so I have designed a re-profiled unit (the ‘SNOW WHITE’ should fit properly!).  I have designed a bonnet which includes the access panel detail, an improved air filter, shock absorbers for the ‘5th wheel’, the tank that sits behind the cab, cab access steps, correct length chain locker and so forth.  A full list and photos to follow.  Oh, there is a vertically orientated pulley that sits on the rear bed of the tractor unit, going to have a go at that later.

[TeeELL]

I am about to construct the Airfix model with the resin printed parts.  

This is test print of the initial designs.  A couple of components needed revising.

 

This is the CAD,  after printing I needed to move the hole for the air-filter forward, significantly reduce the cut out for the radiator cap and reduce the overall height by 0.75mm.

 

This is a representation of the ‘cast style’ air filter


 

This is the vertical pulley that takes the tow rope up to the trailer.  When I scratch built mine, I used a lethe to create the ‘wheel’, this took less than a half hour to design.

 

you can make out these in the first photo.

 

The biggest challenge was the roof which I made a couple of mm too short as I forgot that it extends over the top of the screen.  I also had a go at creating ‘diamond pattern’ sand tyres for the trailer - made them slightly too wide so will use my ‘slicing software’ to reduce the width.

[badger]

Wow - these look amazing!! Would definately be interested in a set if you decide to make these available as the wheels you did were fantastic 👍

[TeeELL]

Badger,

  as I build the test model I am identifying minor corrections needed to the printed parts.  Once I am happy then, of course, I am happy to make the parts available.

[badger]

33 minutes ago, TeeELL said:

Badger,

  as I build the test model I am identifying minor corrections needed to the printed parts.  Once I am happy then, of course, I am happy to make the parts available.

Excellent news. Luckily I hadn't gotten around to starting the Airfix kit yet so these would be a most welcome addition.

 

Following this with interest

 

Kind regards

Ben

[Armor Novice]

I think that there is a slight size difference between the Airfix kit (supposed 1:76), and IBG  (supposedly 1:72).

I would like an idea which is really 1:72 scale. 

I'm watching this thread

[TeeELL]

22 hours ago, Armor Novice said:

I think that there is a slight size difference between the Airfix kit (supposed 1:76), and IBG  (supposedly 1:72).

I would like an idea which is really 1:72 scale. 

I'm watching this thread

The IBG is slightly larger, as you would expect.  However, there are some major errors!  For instance:  Only the earliest TRMU20 tractor units had the same size wheels on all 6 axles, the TRMU30 had 4 larger diameter wheels fitted to the rear.  The IBG TRMU30 has the same wheel sizes all round - it isn’t possible to simply fit larger wheels because the ‘walking beams’ require lengthening.  I did create and print some lengthened ‘walking beams’ for my IBG kit, along with correct size wheels.

[TeeELL]

Much has changed/been revised with my parts for the Airfix Scammell. 
 

The latest enhancements include cab sides, a single piece ‘truck bed’, front and rear tow hooks.

 

This was a ‘mule’ build so I fitted a ‘5th wheel’ with a poorly formed spring.  I suppose I should replace it as I’ve a handful of good prints!

 

[TeeELL]

I still need to decide what, if anything, I can do to enhance the trailer.  Trouble is, the trailer is a late 1943 model so falls outside my period of interest, especially as I have an all resin early style 30-ton trailer.

[TeeELL]

Just for interest:

This is a 1:76 scale resin TRMU20 tractor unit:

 

There are a few errors that need correcting but this model owes nothing to the Airfix kit and has been completely designed from scratch.

 

I received a copy of the 20-ton trailer (late pattern) to couple with it:

 

 

 

[TeeELL]

This is a line-up of 1:76 Scammell tractor units:

on the left is ‘MOLLY’, originally an OOB kit but gradually ‘improved’ with enhanced front axle and walking beams.

center is my conversions on an Airfix ‘mule’

right is an all resin TRMU20

 

’MOLLY’ is looking a bit worse for wear having suffered a few breakages during re-fit programs.  A few detail parts are missing (the rear crew steps for one).

MOLLY still has my modified bed with (old school) scratch built additions,

at center is an early modification of the ‘mule’, still with the original cab sides, the truck bed has the individual enhancements (since replaced with the single piece unit).  
To the right is the all resin TRMU20.